will be found for a safe disposal of oil wastes and for the protection 

 of our inshore waters frcm the devastating , effect of oil pollution. 

 The use of carbonized sand in removing oil slicks may be an important 

 and progressive step in that direction. 



Since there is convincing evidence of the leaching out of toxic 

 substances from oils present in sea water, it is desirable to ascertain 

 whether the conbination of oil with carbonized sand would alter this 

 action. The combination may either lessen the toxicity of the oil, or 

 it may increase it by bringing the poisonous oil closer to the bottom- 

 dwelling forms, permanently anchoring it there, and allowing a slow and 

 continued extraction. 



Before describing in detail our experiments dealing with the toxio 

 effect of oil and sand mixture, we think it is desirable to discuss 

 briefly our observations on the amount of carbonized sand reofuired to 

 submerge a known quantity of oil. 



AMOUNT OF SAND REQUIRED TO SUBMERGE VARIOUS OILS 

 ON SEA WATER OF DIFFERENT SALINITIES. 



The amo\mt of carbonized sand needed to completely submerge oil 

 floating on the surface of water depends on the qusmtity and type of 

 oil used, method of mixing, and the salinity and temperature of the 

 water. The sand supplied by the Norfolk Naval Shipyard for the ex- 

 periments was of very find grade, well coated with carbon. It weighed 

 1.28 grams per ml. To determine the ratio of sand to oil to be used in 

 our experiments, we poured 10 ml. of oil into a finger bowl 178 mm. in 

 diameter containing 500 ml. of sea water. Sand was sprinkled from a small 

 jar, ii\e lid of vrtiich had been punctured with numerous small holes. The 

 amount of sand used was determined by difference in the weight of the jar 

 and its contents before and after the application. To assist in the sink- 

 ing of oil, the water was agitated by tipping the bowl and stirring with 

 a glass rod. The salinity of the undiluted sea water was 31.65 parts per 

 thousand. The results of our tests, which wei^ made in triplicate, are 

 given in table 1. 



For various types of oil on sea water, the amount of sand required 

 to submerge 10 ml. of oil varied from 29.3 to 31.3 grams. As one would 

 expect, an oil slick on fresh water required l^ss sand (25.3 grams). In 

 the case of 50 percent dilution of sea water the amount of sand used 

 occupied an intermediate position (27.0 grams). 



Assuming that one ml. of oil weighs 0.96 grains, we infer that the 

 removal of one pound of oil poured on water would require 3.125 pounds 

 of sand. This figure is about 33 percent greater than the amount given 

 in the report of the Chemical Laboratory (1947), which states that the 



